Australian researchers have evolved a novel way of keeping track of the progress of lung cancer treatment.
The study used a combined PET/CT scanner (positron emission tomography/ computed tomography) scanner and a novel radioactive tracer called FLT or in full 18F-3′-deoxy-3′-fluoro-l-thymidine. FLT targets cells that are rapidly dividing. Once injected, it can highlight cancers that appear not to be responding to therapy.
"At present, there is no other imaging method that can achieve this," says Sarah Everitt, the lead investigator for the study, a PhD student in medical imaging & radiation sciences at Monash University, and a radiation therapist at the Peter MacCallum Cancer Centre.
Lung cancer remains the leading cause of cancer death in Australia. The typical time of survival of patients after diagnosis is less than two years, so improved treatments are needed.
"If we observe a particularly aggressive tumour that grows rapidly during treatment, we can adapt treatment delivery based on the individual's response. This might mean administering the treatment more quickly, or giving a higher radiation dose. Overall, we hope this will improve outcomes and survival of patients with lung cancer and possibly patients with other cancers," says Sarah.
"These scans may also provide us with information that suggests some cancers are not responding to therapy. These patients could then be switched to a different treatment without delay."
The results have also demonstrated how bone marrow behaves during radiation treatment. "One can easily see that bone marrow is extremely sensitive to radiation. Changes are observed after only one day's therapy in a course of six weeks. Because bone marrow produces blood cells, the FLT PET scans could be highly valuable in monitoring patients having large areas of their body irradiated. There may also other scope for these scans, such as monitoring the effects of accidental radiation exposure".
"At present there is no reliable way of monitoring the effectiveness of therapy in killing lung cancer cells during treatment,"
"We hope this information will assist us to tailor treatment according to each individual patient."
"It's also important because, if only a few cells survive of the millions that make up a tumour, then we have failed to cure the patient."